MATLAB utilities for the BYU-MERS "SIR" image format
The BYU-MERS "sir" image format was developed by the Brigham Young
University (BYU) Microwave Earth Remote Sensing (MERS) research group
as part of the NASA Scatterometer Climate Record Pathfinder (SCP) project
to store remotely sensed images of the earth used for climate studies,
among other purposes. The file format stores an image array of floating
point values along with the information required to earth-locate the
image pixels. Additional information on the applications, file format,
and available data can be obtained from the NASA-sponsored Scatterometer
Climate Record Pathfinder web site http://www.scp.byu.edu/ and/or the
NASA/JPL PO.DAAC http://podaac.jpl.nasa.gov/
Files in this directory are useful for reading SIR files into matlab
and locating pixels. Use loadsir.m to load the file into memory. The
routine pix2latlon.m computes the lat/lon position given a list of
x,y pixel locations. latlong2pix does the reverse. showsir and viewsir
are utilities to display SIR images.
Note that these routines use the SIR-standard pixel address from 1 to N.
Note that (1,1) is in the lower left of the image of a SIR File. For an
input location of pixel (1,1) the Lat,Lon values returned by pix2latlon
correspond2 to the location of the lower-left corner of the (1,1)th pixel.
For convenience, matlab-reported values are "flipped" vertically to
the matlab convention.
The matlab routine viewsir.m provides a fancy window utility to read
a SIR file and display to screen. The utility includes zoom and point/click
to get value and location.
Main routines: (version 3.0 SIR format)
loadsir.m loads image and header information into matlab
loadpartsir.m loads part of image and header information into matlab
printsirhead.m prints out the header information from loadsir
pix2latlon.m given a pixel location, compute lat and lon
latlon2pix.m compute pixel location given lat and lon
sirheadtext.m modifies text fields of sir header before write
writesir.m writes sir format file
Geometry and Support routines:
easegrid.m forward EASE grid transformation
ieasegrid.m inverse EASE grid transformation
ilambert1.m inverse Lambert grid transformation
ipolster.m inverse polar stereographic grid transformation
lambert1.m forward Lambert grid transformation
mod.m compute modulo function
polster.m forward polar stereographic grid transformation
Other files:
Contents.m Matlab help file
readme_matlab.txt this file
scaleimage.m utility to scale image for display
showsir.m simplified display routine for sir image
viewsir.m function interface for viewsir1.m to display SIR image
viewsir1.m called by viewsir
sircolorbar.m callled by viewsir1
sir_locate.m interactively select a point on image and print location
setsirhead.m set particular values in sir header by name
sirheadvalue.m get particular values in sir header by name
sirheadtext.m set text values in sir header
display_head.m help routine for sirheadvalue
Note: when using writesir it is recommended that the header from an existing
SIR file be used at a template and only the changed fields modified.
If you have any questions, please contact the SCP.
==============================================================================
Dr. David G. Long long@ee.byu.edu
Director, BYU Center for Remote Sensing http://www.cers.byu.edu/
Professor, Electrical and Computer Eng. Dept. http://www.ee.byu.edu/
Brigham Young University http://www.byu.edu/
459 Clyde Building voice: 801-422-4383
Provo, Utah 84602 fax: 801-422-0201
Microwave Earth Remote Sensing (MERS) Lab: http://www.mers.byu.edu/
Scatterometer Climate Record Pathfinder: http://www.scp.byu.edu/
==============================================================================
Last revised: 25 Apr 2003 DGL
(c) 1997, 1998, 1999, 2000, 2002, 2003 BYU MERS